棉花主要栽培生理参数的高光谱估测研究

 应用地物光谱仪获取近地高光谱遥感数据 ,用高光谱技术提取和估计棉花主要栽培生理参数。结果表明 ,棉花叶片具有绿色植物典型的反射光谱曲线特征 ;早衰的棉花反射光谱红谷区谷低变浅 ,最小波段光谱反射率Ro及数值积分面积SRo增大 ,与叶片光合速率呈显著负相关。经逐步回归分析 ,确定的一阶微分光谱值与棉叶叶绿素浓度的最大相关系数是 0 .734 4 (n =2 1) ,发生在 75 0nm波段处 ;群体叶面积指数 (LAI)与归一化差值植被指数 (ND VI)呈很好的对数相关关系 ;红边、蓝边、黄边每边的积分面积积累了多波段信息 ,在估测棉花冠层叶片全氮含量中有较大的应用潜力。研究建立了棉花主要栽培生理参数叶绿素含量、LAI和冠层叶片全氮含量等的遥感估测统计模型。

Estimating of Main Cultivation Physiology Parameters of Cotton by Using Hyperspectral Remote Sensing

Based on hyperspectral observation of cotton leaf in Xinjiang, the relationship between the characteristics of hyperspectral data and main cultivation physiology parameters was analyzed. The results showed that cotton have typical reflectance spectra characteristics as normal plants. The reflectance of leaf in senescence must be rise up in Red Valley Region (640-680 nm), which showed a high negative relationship with leaf photosynthesis rates. There was a high positively correlation between the first derivative spectral data and the chlorophyll content of cotton leaf in some bands, especially in 723-849nm, and the maximum value of correlation coefficient (r=0.7344) in waveband 750 nm, by using multivariate regression analyzing. NDVI (normalized difference vegetation index) was logarithmic correlation with LAI. Each area of Red Edge, Blue Edge and Yellow Edge accumulated the information of more channels, so they had larger application potential capacity to estimate total nitrogen content in leaf. And based on the relationship between them, some statistical models of the main physiology parameters have been established,such as LAI, chlorophyll content, total nitrogen content etc, which could be estimated by the hyperspectral data.